<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

</head>
<body>
<span id="your-name"></span>
<input id="to" value="all"/>
<input id="text"/>
<button onclick="send()" type="button">发送</button>
    <div id="message"></div>
</body>
<script>
    var websocket = null;
    var name=window.prompt("your name");
    document.getElementById("your-name").innerText=name;
    if('WebSocket' in window) {
        websocket = new WebSocket(`ws://${window.location.host}/websocket/${name}`);
    }
    //
    //连接发生错误的回调方法
    websocket.onerror = function () {
        setMessageInnerHTML("WebSocket连接发生错误");
    };

    //连接成功建立的回调方法
    websocket.onopen = function () {
        setMessageInnerHTML("WebSocket连接成功");
    }

    //接收到消息的回调方法
    websocket.onmessage = function (event) {
        setMessageInnerHTML(event.data);
    }

    //连接关闭的回调方法
    websocket.onclose = function () {
        setMessageInnerHTML("WebSocket连接关闭");
    }

    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
    window.onbeforeunload = function () {
        closeWebSocket();
    }

    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML) {
        //let u=JSON.parse(innerHTML);
        document.getElementById('message').innerHTML +=innerHTML + '<br/>';
    }

    //关闭WebSocket连接
    function closeWebSocket() {
        websocket.close();
    }

    //发送消息
    function send() {
        var message = document.getElementById('text').value;
        document.getElementById('text').value="";
        let obj={to:document.getElementById("to").value,msg:message};
        websocket.send(JSON.stringify(obj));
    }
</script>

</html>